CN116286146A

CN116286146A - Vehicle gear oil composite additive, preparation method and application thereof

Info

Publication number: CN116286146A
Application number: CN202310090354.9A
Authority: CN
Inventors: 张兆钧; 李久盛; 路捷; 张春风; 张晓军; 张伟; 王李杨; 胡文敬; 田晔; 吴天杰
Original assignee: Shanxi Lu'an Taihang Lubrication Technology Co ltd; Shanghai Advanced Research Institute of CAS
Current assignee: Shanxi Lu'an Taihang Lubrication Technology Co ltd; Shanghai Advanced Research Institute of CAS
Priority date: 2023-02-09
Filing date: 2023-02-09
Publication date: 2023-06-23

Abstract

The invention provides a vehicle gear oil composite additive, a preparation method and application thereof, wherein the composite additive comprises the following components in parts by mass: 18 to 80 parts of sulfide extreme pressure agent, 10 to 30 parts of antiwear agent, 0 to 10 parts of sulfur-free phosphorus type friction modifier, 10 to 50 parts of detergent dispersant, 0 to 10 parts of antioxidant, 0 to 5 parts of metal deactivator and 0.1 to 1 part of anti-foaming agent. According to the invention, 12.0wt% of the composite additive is added into the base oil, so that the extreme pressure antiwear property of the oil product is excellent; the composite additive has excellent solubility, the oil product can be prepared at normal temperature without heating, the appearance and the foam resistance of the oil product are qualified, the energy consumption in the oil product blending process is greatly reduced, the blending efficiency is improved, and the production cost is reduced; in addition, the wear-resistant oil product has good high-temperature oxidation resistance, oil sludge is not easy to generate at high temperature, and the wear resistance of the oil product is kept good after high-temperature decay.

Description

Vehicle gear oil composite additive, preparation method and application thereof

Technical Field

The invention belongs to the technical field of gear oil, and particularly relates to a vehicle gear oil composite additive, a preparation method and application thereof.

Background

With the development and progress of technology, the carrier vehicles are developed towards the directions of environmental protection, light weight and heavy load, the energy density of the vehicle gearbox and the axle gear set is continuously improved, the influence of lubrication on the reliability, service life and energy consumption of a transmission component is further increased, and therefore the extreme pressure wear resistance requirement on the vehicle gear oil is also higher. The continuous pursuit of the whole life cycle of the whole vehicle to integrate low operation and maintenance cost and long maintenance cycle requires gear oil to have longer oil change mileage, thereby pushing the requirement of original equipment manufacturers on extreme pressure long-life (oil change mileage >20 ten thousand kilometers) vehicle gear oil.

Through years of development, the vehicle gear oil composite additive is subjected to development stages such as sulfur-phosphorus-chlorine, sulfur-phosphorus-chlorine-zinc, sulfur-phosphorus-nitrogen-boron and the like, the comprehensive performance of the oil is gradually improved, but the extreme pressure wear resistance and the heat-resistant and oxygen-resistant performance of the vehicle gear oil are always contradictions which are difficult to balance. In the service process of the oil product, if the extreme pressure wear resistance of the gear oil is insufficient, the temperature of a gear meshing area is easy to be higher, so that the oxidation and deterioration of the oil product are accelerated, the service life of the oil product is greatly shortened, and the long-time lubrication requirement under the severe working condition is difficult to meet. Therefore, the additive compounding technology ensures that the vehicle gear oil has better heat resistance and oxidation resistance and simultaneously has better extreme pressure wear resistance, meets the performance requirements of low odor, corrosion resistance and rust resistance, rubber compatibility, material compatibility and the like of the vehicle gear oil, and meets the development trend of long oil change mileage of the current gear oil compound additive.

In addition, in order to improve the service life of the vehicle gear oil, the synthetic base oil of API III and above is widely used in the vehicle gear oil, but the synthetic base oil, especially the synthetic hydrocarbon base oil, has poor solubility to the composite additive, and the vehicle gear oil composite additive developed for mineral base oil with relatively good solubility in the early stage has poor solubility and long-term storage stability in the synthetic hydrocarbon base oil, so that the application of the traditional vehicle gear oil composite additive in the synthetic base oil is limited, the selection range of the synthetic vehicle gear oil composite additive is less, and the popularization and application of the synthetic vehicle gear oil are influenced.

In order to obtain a homogeneous and transparent gear oil product, the conventional gear oil blending process generally needs to heat base oil to above 45-60 ℃, and gear oil additives and anti-foaming agents can be added, and the gear oil can be canned after blending is finished and the oil product is required to wait for cooling. The energy required to raise the temperature of 1 ton of lubricating oil to 40 ℃ is about 75000KJ by accounting for energy transferLoss in the delivery process, about 33.3kg of standard coal or 78.9 kW.h of electricity is consumed for heating 1 ton of oil products, and CO is caused ₂ The discharge amount is about 40-50kg, so that the conventional gear oil blending process is complex, the blending efficiency is low, and a large amount of energy is consumed to heat the oil, so that energy waste and carbon emission are caused.

Therefore, developing a gear oil composite additive which can be blended at normal temperature without heating has important significance for improving the carbon emission in the oil production process.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention is directed to a vehicle gear oil composite additive, a preparation method and an application thereof, which are used for solving the problems of conflict of extreme pressure antiwear performance and heat-resistant antioxidant performance and poor solubility in synthetic base oil of the vehicle gear oil composite additive in the prior art, and the problems of energy waste and carbon emission caused by consumption of a large amount of energy in the blending process of the gear oil.

In order to achieve the above and other related objects, the invention provides a vehicle gear oil composite additive, which is characterized by comprising the following components in parts by mass: 18 to 80 parts of sulfide extreme pressure agent, 10 to 30 parts of antiwear agent, 0 to 10 parts of sulfur-free phosphorus type friction modifier, 10 to 50 parts of detergent dispersant, 0 to 10 parts of antioxidant, 0 to 5 parts of metal deactivator and 0.1 to 1 part of anti-foaming agent.

Preferably, the composite additive comprises the following components in parts by mass: 28-70 parts of sulfide extreme pressure agent, 14-25 parts of antiwear agent, 0-10 parts of sulfur-free phosphorus type friction modifier, 15-40 parts of detergent dispersant, 3-6 parts of antioxidant, 0-3 parts of metal deactivator and 0.1-0.5 part of anti-foaming agent.

Preferably, the sulfide extreme pressure agent is one or a combination of high-pressure vulcanized olefin and normal-pressure vulcanized olefin, wherein the sulfur content in the high-pressure vulcanized olefin is 42-46 wt%; the sulfur content in the normal pressure vulcanized olefin is 40-45 wt%.

Preferably, the antiwear agent is one or a combination of acid phosphate amine salt and nitrogen heterocyclic phosphite amine salt.

Preferably, the sulfur-free phosphorus type friction modifier is an amine compound, and the structural general formula of the amine compound is as follows:

wherein the group R is selected from H, C ₈ ～C ₁₈ Straight chain alkyl or C ₈ ～C ₁₈ Branched alkyl groups.

Preferably, the detergent dispersant is one or a combination of polyisobutylene succinimide and boronated polyisobutylene succinimide.

Preferably, the antioxidant is one or a combination of shielding phenol and aromatic amine.

Preferably, the metal deactivator is one or a combination of benzotriazole, thiadiazole and imidazoline derivatives.

Preferably, the anti-foaming agent is one or a combination of organosilicon polymer and non-organosilicon polymer.

The preparation method of the vehicle gear oil composite additive comprises the following steps:

the sulfide extreme pressure agent, the antiwear sulfur-free phosphorus friction modifier, the detergent dispersant, the antioxidant, the metal deactivator and the anti-foaming agent are sequentially added into a reaction vessel according to the proportion of the raw materials, stirred for 60-120 min at the temperature of 60-80 ℃ at the rotating speed of 200-500 rmp, cooled and filtered to obtain the vehicle gear oil composite additive.

In order to further improve the extreme pressure property and reduce the odor of the vehicle gear oil composite additive, the invention also provides a preparation method of the vehicle gear oil composite additive, which comprises the following steps:

s1, heating sulfide extreme pressure agent and antiwear agent according to the component proportion at 100-120 ℃ for reaction for 60-120 min to obtain mixed solution;

s2, cooling the mixed solution to 60-80 ℃, adding a sulfur-free phosphorus type friction modifier, a detergent dispersant, an antioxidant, a metal deactivator and an anti-foaming agent according to mass ratio, stirring for 60-120 min at a rotating speed of 200-500 rmp, cooling, and filtering to obtain the vehicle gear oil composite additive.

The application of the composite additive for the vehicle gear oil, which is applied to the vehicle gear oil, wherein the adding amount of the composite additive in the gear oil is not more than 12wt percent based on 100% of the mass of the gear oil.

As described above, the vehicle gear oil composite additive, the preparation method and the application thereof of the invention have the following beneficial effects:

the vehicle gear oil composite additive adopts the mixture of high-pressure vulcanized olefin and/or normal-pressure vulcanized olefin as a sulfide extreme pressure agent, and various phosphorus-nitrogen additives as antiwear agents; in addition, the composite additive contains a detergent dispersant and an anti-foaming agent, so that the anti-foaming agent is firstly uniformly dispersed in the composite additive, and the phenomenon that the oil is heated and severely stirred to ensure that the anti-foaming performance of the oil is qualified during oil blending is avoided; the composite additive has excellent solubility in API III and above total synthetic base oil, and if the base oil component does not contain super-viscosity components such as viscosity index improver (100 ℃ kinematic viscosity is greater than 200 mm) ² And s), the oil product can be prepared at normal temperature without heating, and the appearance and the anti-foam performance of the oil product are not obviously changed after long-term storage, so that the energy consumption in the oil product blending process is greatly reduced, the blending efficiency is improved, and the oil product production cost is reduced.

The vehicle gear oil composite additive contains a sulfur-free and phosphorus-free friction improver, wherein a nitrogen atom in the structure of the sulfur-free and phosphorus-free friction improver is provided with lone pair electrons, an ordered molecular adsorption film is formed on the surface of a metal, friction and abrasion on the surface of a metal friction pair are reduced, and the anti-friction performance of lubricating oil is improved, so that the temperature rise of the oil in the use process is inhibited; in addition, the compound additive takes shielding phenol and aromatic amine as antioxidants and is matched with the oil sludge dispersing effect of a detergent dispersant and an antiwear agent with good thermal stability, so that the compound additive has good high-temperature oxidation resistance, insoluble matters such as oil sludge and the like are not easy to generate at high temperature, and the antiwear performance of an oil product after high-temperature decay is kept good, thereby improving the oil change mileage of the oil product, and the oil change mileage of the oil product prepared by the compound additive is more than 20 ten thousand kilometers; in addition, the vehicle gear oil composite additive can pass the liquid phase corrosion test of synthetic seawater without adding an antirust agent, and the salt fog resistance of the oil prepared by the additive is better than that of conventional gear oil, so that gears can be effectively protected from corrosion and corrosion, and the service life of a gear set is prolonged.

According to the invention, 12.0wt% of the composite additive is added into the blended 75W-140 viscosity grade base oil, the antiwear property of the oil is obviously superior to that of the oil prepared by various commercial high-end vehicle gear oil composite additives, and the gear set running under high load can be well protected.

Drawings

FIG. 1 shows the friction coefficient curves of the oil products prepared in example 1, example 5, comparative example 2 and comparative example 4 according to the present invention, which are obtained by performing a heavy load variable speed test.

FIG. 2 is a graph showing the comparison of the diameter of the grinding marks obtained by carrying out a heavy load variable speed test on the oil product prepared in example 1 of the present invention.

FIG. 3 is a graph showing the comparison of the diameter of the grinding marks obtained after the heavy load rotation speed test of the oil product prepared in example 5 of the present invention.

FIG. 4 is a graph showing the comparison of the diameter of the grinding marks obtained after the heavy load rotation speed test of the oil product prepared in comparative example 2 according to the present invention.

FIG. 5 is a graph showing the comparison of the diameter of the grinding marks obtained after the heavy load rotation speed test of the oil product prepared in comparative example 4 according to the present invention.

FIG. 6 is a graph showing the amounts of sludge produced after oven oxidation in the oil life test for the oil products prepared in examples 1, 5, 2, 3 and 5 according to the present invention.

FIG. 7 is a graph showing the temperature change of the oil products prepared in examples 1, 2, 5, 2 and 4 according to the present invention during the heavy load variable rotation speed test.

Detailed Description

Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.

The invention provides a vehicle gear oil composite additive which comprises the following components in parts by mass: 18 to 80 parts of sulfide extreme pressure agent, 10 to 30 parts of antiwear agent, 0 to 10 parts of sulfur-free phosphorus type friction modifier, 10 to 50 parts of detergent dispersant, 0 to 10 parts of antioxidant, 0 to 5 parts of metal deactivator and 0.1 to 1 part of anti-foaming agent.

Specifically, the sulfide extreme pressure agent may include any range of values of 18 parts, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, etc., the antiwear agent may include any range of values of 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, etc., the sulfur-free phosphorus type friction modifier may include any range of values of 0 parts, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, etc., the detergent-dispersant may include any range of values of 10 parts, 20 parts, 30 parts, 40 parts, 50 parts, etc., the antioxidant may include any range of values of 0 parts, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, etc., the metal deactivator may include any range of values of 0 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc., and the anti-foaming agent may include any range of values of 0.1 parts, 0.3 parts, 0.5 parts, 0.7 parts, 0.9 parts, 1 part, etc.

As an example, the composite additive comprises the following components in parts by mass: 28 to 70 parts (such as 28 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, etc.), 14 to 25 parts (such as 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 25 parts, etc.), 0 to 10 parts (such as 0 parts, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, etc.), 15 to 40 parts (such as 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, etc.), 3 to 6 parts (such as 3 parts, 4 parts, 5 parts, 6 parts, etc.), 0 to 3 parts (such as 0 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, etc.), 0.1 to 0.5 parts (such as 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, etc.), of an anti-foaming agent.

As an example, the sulfide extreme pressure agent is one or a combination of high pressure sulfurized olefins, normal pressure sulfurized olefins, wherein the sulfur content in the high pressure sulfurized olefins is 42-46 wt% (e.g., 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, etc.); the sulfur content in the atmospheric sulfur olefin is 40 to 45wt% (such as 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, etc.).

Specifically, the high-pressure vulcanized olefin is vulcanized olefin which is produced by carrying out high-pressure reaction on olefin and elemental sulfur in an alkaline environment, and the one-step synthesis is carried out on the vulcanized olefin, and the normal-pressure vulcanized olefin is vulcanized olefin produced by two steps of sulfur chlorination and sulfur dechlorination of isobutene under normal pressure.

Preferably, when the sulfide extreme pressure agent is a mixture of high pressure sulfide olefin and normal pressure sulfide olefin, the proportion of the normal pressure sulfide olefin in the sulfide extreme pressure agent is 20wt% to 40wt%.

Since the high-pressure vulcanized olefin has lower corrosion to metals than the normal-pressure vulcanized olefin, in the components of the composite additive, when the content of the normal-pressure vulcanized olefin in the sulfide extreme pressure agent is less than 30wt%, no metal deactivator is added.

Specifically, the high-pressure vulcanized olefin has the advantages of low corrosiveness, small smell, good oil solubility, high extreme pressure and the like, but has obvious swelling and dissolving effects on rubber and paint, and poor lubricating performance; the normal pressure vulcanized olefin has the advantages of good lubricating property, insignificant swelling and dissolution effects on rubber and paint, and the like, but has larger corrosiveness; the performance characteristics of the vulcanized olefins prepared by different processes can be exerted by mixing the normal-pressure vulcanized olefins and the high-pressure vulcanized olefins.

As an example, the antiwear agent is one or a combination of acid phosphate amine salt, nitrogen-containing heterocyclic phosphite amine salt.

Specifically, phosphide and derivatives thereof in the phosphorus antiwear agent are firstly adsorbed on the metal surface, and undergo tribochemical reaction in a rubbed extreme pressure state to generate organic phosphate, organic phosphite, organic phosphate polymer and inorganic phosphate (ferric phosphite, ferric phosphate hydrate, ferric oxide and the like), so as to form a physical adsorption film and a chemical reaction film to play a role in extreme pressure antiwear; the sulfide in the extreme pressure agent is thermally decomposed to generate high-melting-point ferric sulfide under the condition of high-speed impact load, so that the damage of the tooth surface can be effectively prevented; according to the specific embodiment of the invention, the synergistic effect of the sulfide extreme pressure agent and the antiwear agent is fully exerted, so that the composite additive has excellent extreme pressure antiwear property.

As an example, the sulfur-free and phosphorus-free friction modifier is an amine compound having the structural formula:

Specifically, the nitrogen atoms in the structure of the sulfur-free phosphorus friction improver have lone pair electrons, an ordered molecular adsorption film is formed on the surface of the metal, friction and abrasion on the surface of a metal friction pair are reduced, and the anti-friction performance of lubricating oil is improved, so that the temperature rise of the oil product in the use process is inhibited; the sulfur-free phosphorus type friction modifier is an amine compound, and the preparation method comprises the following steps: organic amine is used as a reaction substrate, dichloromethane is used as a solvent, long-chain fatty acyl chloride reacts with the organic amine to generate amide under the action of triethylamine, and the amide is reduced by lithium aluminum hydride to prepare the corresponding amine compound.

As an example, the detergent dispersant is one or a combination of polyisobutylene succinimide, boronated polyisobutylene succinimide.

As an example, the antioxidant is one or a combination of a shielding phenol and an aromatic amine.

Specifically, the shielding phenol and/or aromatic amine are used as an antioxidant, and the oil sludge dispersing effect of the detergent dispersant and the antiwear agent with good thermal stability are matched, so that the composite additive has good high-temperature oxidation resistance, insoluble matters such as the oil sludge are not easy to generate at high temperature, and the antiwear performance of the oil product after high-temperature decay is kept good, thereby improving the oil change mileage of the oil product.

As an example, the metal deactivator is one or a combination of benzotriazole, thiadiazole, and imidazoline derivatives.

As an example, the anti-foaming agent is one or a combination of silicone polymers and non-silicone polymers.

Specifically, the anti-foaming agent is uniformly dispersed in the composite additive in advance, so that the phenomenon that the oil is heated and severely stirred in order to ensure that the anti-foaming performance of the oil is qualified in later-stage oil blending is avoided; preferably, the anti-foaming agent in the specific embodiment of the invention is one or a combination of polymethyl silicone oil, acrylic ester and ether copolymer.

The composite additive of the invention contains both a quiet dispersant and an anti-foaming agent, and the clean dispersant has good sludge dispersing effect, so that the composite additive has excellent solubility in API III and above total synthetic base oil, and if the base oil component does not contain super-large viscosity components such as viscosity index improver and the like (the kinematic viscosity at 100 ℃ is more than 200 mm) ² And s), the oil product can be prepared without heating at normal temperature (15-35 ℃) to obtain the oil product with qualified appearance and anti-foam performance, and the appearance and the anti-foam performance of the oil product are still not changed obviously after long-term storage, so that the energy consumption in the oil product blending process is greatly reduced, the blending efficiency is improved, and the oil product production cost is reduced.

In order to better understand the vehicle gear oil composite additive, the invention also provides a preparation method of the vehicle gear oil composite additive, which comprises the following steps: a method for preparing a vehicle gear oil composite additive, comprising the following steps: according to the component proportion, the sulfide extreme pressure agent, the antiwear agent, the sulfur-free phosphorus friction improver, the detergent dispersant, the antioxidant, the metal deactivator and the anti-foaming agent are added into a reaction container, heated to 60 ℃ -80 ℃ (such as 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃ and any range of values, and can be specifically regulated according to the actual condition), stirred for 60-120 min (such as 60min, 70min, 80min, 90min, 100min, 110min, 120min and any range of values with 200-500 rpm (such as 200, 300, 400, 500 and any range of values, and can be specifically regulated according to the actual condition) at a rotating speed of 200-500 rpm (such as 200, 300, 400, 500 and any range of values), cooled and filtered to obtain the vehicle gear oil composite additive.

In order to further improve the extreme pressure performance and reduce the odor of the vehicle gear oil composite additive, the preparation of the composite additive comprises the following steps:

s1, heating sulfide extreme pressure agent and antiwear agent at 100-120 ℃ (such as values in any range of 100, 105, 110, 115, 120 and the like, and specifically can be adjusted according to actual conditions) for reaction for 60-120 min (such as values in any range of 60min, 70min, 80min, 90min, 100min, 110min, 120min and the like, and specifically can be adjusted according to actual conditions) according to the component proportion to obtain mixed liquid;

S2, cooling the mixed solution to a value in any range of 60-80 ℃ (such as 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃ and the like, and specifically adjusting according to the actual conditions), adding a sulfur-free phosphorus friction improver, a detergent dispersant, an antioxidant, a metal deactivator and an anti-foaming agent according to the mass ratio, stirring at a rotating speed of 200-500 rmp (such as values in any range of 200, 300, 400, 500 and the like, specifically adjusting according to the actual conditions) for 60-120 min (such as values in any range of 60min, 70min, 80min, 90min, 100min, 110min, 120min and the like, specifically adjusting according to the actual conditions), cooling, and filtering to obtain the vehicle gear oil composite additive.

The invention also provides application of the composite additive for the vehicle gear oil, which is applied to the vehicle gear oil, wherein the adding amount of the composite additive in the gear oil is not more than 12wt% based on 100% of the mass of the gear oil, and the blending production of the gear oil can be realized without heating.

Specifically, the addition amount of the composite additive in the gear oil may include a value other than 0wt% in any range of 12wt%, 11.5wt%, 11wt%, 10.5wt%, 10wt%, 1wt%, 0wt% and the like, based on 100% by mass of the gear oil, and may be specifically adjusted according to the actual use; in actual use, 12wt% of the composite additive is added into blended 75W-140 viscosity grade base oil, the antiwear property of the oil is obviously superior to that of the oil prepared by various commercial high-end vehicle gear oil complexing agents, and the gear set running under high load is well protected; the addition of 12wt% of the composite additive to 75W-140 and 75W-90 viscosity grade fully synthetic base oil has the pungent smell and rubber compatibility equivalent to those of similar compounding agent products.

For a better understanding of the vehicle gear oil composite additive, the method of preparation and the use thereof of the present invention, the vehicle gear oil composite additive, the method of preparation and the use thereof of the present invention are described below with reference to specific examples, which should be construed as merely illustrative, and not limiting of the present invention in any way.

Example 1

The invention provides a vehicle gear oil composite additive which comprises the following components in parts by mass: 58 parts of sulfide extreme pressure agent, 19 parts of antiwear agent, 0 part of sulfur-free and phosphorus-free friction modifier, 36.5 parts of detergent dispersant, 0 part of antioxidant, 0 part of metal deactivator and 0.15 part of anti-foaming agent; wherein the sulfide extreme pressure agent is high-pressure sulfide olefin; the antiwear agent is prepared by compounding acid phosphate amine salt and nitrogen-containing heterocyclic phosphite amine salt, and the compounding ratio of the acid phosphate amine salt to the nitrogen-containing heterocyclic phosphite amine salt is 3.5:15.5; the detergent dispersant is compounded by polyisobutylene succinimide and boronated polyisobutylene succinimide, and the compounding ratio of the polyisobutylene succinimide to the boronated polyisobutylene succinimide is 30:6.5; the anti-foaming agent is formed by compounding an organosilicon polymer and a non-organosilicon polymer, and the compounding ratio is 1:1.

The invention also provides a preparation method of the vehicle gear oil composite additive, which comprises the steps of adding 58 parts of sulfide extreme pressure agent, 19 parts of antiwear agent, 36.5 parts of detergent dispersant and 0.15 part of anti-foaming agent into a reaction container, heating to 60 ℃, stirring for 60min at a rotating speed of 500rpm, cooling and filtering to obtain the vehicle gear oil composite additive.

Example 2

The invention provides a vehicle gear oil composite additive which comprises the following components in parts by mass: 58 parts of sulfide extreme pressure agent, 19 parts of antiwear agent, 6.5 parts of sulfur-free and phosphorus-free friction modifier, 30 parts of detergent dispersant, 5.5 parts of antioxidant, 0 part of metal deactivator and 0.15 part of anti-foaming agent; wherein the sulfide extreme pressure agent is high-pressure sulfide olefin; the antiwear agent is prepared by compounding acid phosphate amine salt and nitrogen-containing heterocyclic phosphite amine salt, and the compounding ratio of the acid phosphate amine salt to the nitrogen-containing heterocyclic phosphite amine salt is 9:10; the sulfur-free phosphorus type organic friction modifier is N, N, N' -tri-N-octyl-tri (2-amino ethyl) amine; the detergent dispersant is compounded by polyisobutylene succinimide and boronated polyisobutylene succinimide, and the compounding ratio of the polyisobutylene succinimide to the boronated polyisobutylene succinimide is 5:1, a step of; the antioxidant is formed by compounding shielding phenol and aromatic amine, and the compounding ratio of the shielding phenol to the aromatic amine is 5:6, preparing a base material; the anti-foaming agent is formed by compounding an organosilicon polymer and a non-organosilicon polymer, and the compounding ratio of the organosilicon polymer to the non-organosilicon polymer is 1:1.

Specifically, the preparation method of the N, N, N' -tri-N-octyl-tri (2-amino ethyl) amine comprises the following steps:

a1, dissolving 5.0g of tri (2-aminoethyl) amine and 13.8g of triethylamine in a reaction bottle filled with 200mL of dichloromethane, dropwise adding 16.8g of octanoyl chloride into the reaction bottle in an ice bath, removing the ice bath after the dropwise adding, and reacting for 12 hours at room temperature;

A2, adding 200ml of water into the reaction bottle, and separating an organic phase;

a3, washing the organic phase with 100ml of water for three times, drying the organic phase with anhydrous sodium sulfate, and evaporating the solvent under reduced pressure to obtain a crude product;

a4, recrystallizing the crude product by using dichloromethane and petroleum ether to obtain 17.1g of octanamide derivative of the tri (2-amino ethyl) amine;

a5, dissolving 4.0g of the octanamide derivative of the tri (2-aminoethyl) amine in 150ml of anhydrous tetrahydrofuran, adding 1.2g of lithium aluminum hydride in batches under ice bath, heating to reflux under the protection of nitrogen, continuing to react for 48 hours, cooling the reaction liquid to room temperature, adding 6ml of water into the reaction liquid, stirring until bubbles are completely released, adding 150ml of dichloromethane and a proper amount of anhydrous sodium sulfate, stirring until the mixture is clear, filtering, and evaporating the filtrate to remove the solvent to obtain 3.2g of target product N, N, N' -tri-N-octyl-tri (2-aminoethyl) amine.

The invention also provides a preparation method of the vehicle gear oil composite additive, which comprises the steps of adding 58 parts of sulfide extreme pressure agent, 19 parts of antiwear agent, 6.5 parts of sulfur-free phosphorus type friction modifier, 30 parts of detergent dispersant, 5.5 parts of antioxidant and 0.15 part of anti-foaming agent into a reaction container, heating to 60 ℃, stirring at 500rpm for 60min, cooling, and filtering to obtain the vehicle gear oil composite additive.

Example 3

The invention provides a vehicle gear oil composite additive which comprises the following components in parts by mass: 58 parts of sulfide extreme pressure agent, 19 parts of antiwear agent, 0 part of sulfur-free and phosphorus-free friction modifier, 36.5 parts of detergent dispersant, 5.5 parts of antioxidant, 0 part of metal deactivator and 0.15 part of anti-foaming agent; wherein, the sulfide extreme pressure agent is formed by compounding high-pressure vulcanized olefin and normal-pressure vulcanized olefin, and the compounding ratio is 18:40, a step of performing a; the antiwear agent is prepared by compounding acid phosphate amine salt and nitrogen-containing heterocyclic phosphite amine salt, and the compounding ratio of the acid phosphate amine salt to the nitrogen-containing heterocyclic phosphite amine salt is 9:10; the detergent dispersant is compounded by polyisobutylene succinimide and boronated polyisobutylene succinimide, and the compounding ratio of the polyisobutylene succinimide to the boronated polyisobutylene succinimide is 30:6.5; the antioxidant is compounded by shielding phenol and aromatic amine, and the compounding ratio is 5:6, preparing a base material; the anti-foaming agent is formed by compounding an organosilicon polymer and a non-organosilicon polymer, and the compounding ratio is 1:1.

The invention also provides a preparation method of the vehicle gear oil composite additive, which comprises the steps of adding 58 parts of sulfide extreme pressure agent, 19 parts of antiwear agent, 36.5 parts of detergent dispersant, 5.5 parts of antioxidant and 0.15 part of anti-foaming agent into a reaction container, heating to 60 ℃, stirring for 60min at a rotating speed of 500rpm, cooling, and filtering to obtain the vehicle gear oil composite additive.

Example 4

The invention provides a vehicle gear oil composite additive which comprises the following components in parts by mass: 58 parts of sulfide extreme pressure agent, 19 parts of antiwear agent, 6.5 parts of sulfur-free and phosphorus-free friction modifier, 30 parts of detergent dispersant, 5.5 parts of antioxidant, 1 part of metal deactivator and 0.15 part of anti-foaming agent; wherein the sulfide extreme pressure agent is formed by compounding high-pressure vulcanized olefin and normal-pressure vulcanized olefin, and the compounding ratio is 18:40; the antiwear agent is prepared by compounding acid phosphate amine salt and nitrogen-containing heterocyclic phosphite amine salt, and the compounding ratio of the acid phosphate amine salt to the nitrogen-containing heterocyclic phosphite amine salt is 9:10; the sulfur-free phosphorus type organic friction modifier is N, N, N' -tri-N-octyl-tri (2-amino ethyl) amine, and the preparation method is the same as that in the embodiment 2, and is not repeated here; the detergent dispersant is compounded by polyisobutylene succinimide and boronated polyisobutylene succinimide, and the compounding ratio of the polyisobutylene succinimide to the boronated polyisobutylene succinimide is 5:1; the antioxidant is compounded by shielding phenol and aromatic amine, and the compounding ratio is 5:6, preparing a base material; the metal deactivator is a thiadiazole derivative; the anti-foaming agent is formed by compounding an organosilicon polymer and a non-organosilicon polymer, and the compounding ratio is 1:1.

The invention also provides a preparation method of the vehicle gear oil composite additive, which comprises the steps of adding 58 parts of sulfide extreme pressure agent, 19 parts of antiwear agent, 6.5 parts of sulfur-free phosphorus type friction modifier, 30 parts of detergent dispersant, 5.5 parts of antioxidant, 1 part of metal deactivator and 0.15 part of anti-foaming agent into a reaction container, heating to 60 ℃, stirring at 500rpm for 60min, cooling and filtering to obtain the vehicle gear oil composite additive.

Example 5

The invention provides a vehicle gear oil composite additive which comprises the following components in parts by mass: 58 parts of sulfide extreme pressure agent, 19 parts of antiwear agent, 0 part of sulfur-free and phosphorus-free friction modifier, 36.5 parts of detergent dispersant, 5.5 parts of antioxidant, 1 part of metal deactivator and 0.15 part of anti-foaming agent; wherein the sulfide extreme pressure agent is formed by compounding high-pressure vulcanized olefin and normal-pressure vulcanized olefin, and the compounding ratio is 18:40; the antiwear agent is prepared by compounding acid phosphate amine salt and nitrogen-containing heterocyclic phosphite amine salt, and the compounding ratio of the acid phosphate amine salt to the nitrogen-containing heterocyclic phosphite amine salt is 9:10; the detergent dispersant is compounded by polyisobutylene succinimide and boronated polyisobutylene succinimide, and the compounding ratio of the polyisobutylene succinimide to the boronated polyisobutylene succinimide is 30:6.5; the antioxidant is compounded by shielding phenol and aromatic amine, and the compounding ratio is 5:6, preparing a base material; the metal deactivator is a thiadiazole derivative; the anti-foaming agent is formed by compounding an organosilicon polymer and a non-organosilicon polymer, and the compounding ratio is 1:1.

The invention also provides a preparation method of the vehicle gear oil composite additive, which comprises the steps of adding 40 parts of normal pressure vulcanized olefin and 10 parts of nitrogen heterocyclic phosphite amine salt into a reaction vessel, heating to 120 ℃ and stirring for reaction for 60min to obtain a mixed solution; and then cooling the mixed solution to 60 ℃, adding 18 parts of the rest high-pressure vulcanized olefin, 9 parts of acid phosphate amine salt, 36.5 parts of detergent dispersant, 5.5 parts of antioxidant, 1 part of metal deactivator and 0.15 part of anti-foaming agent, stirring for 60 minutes at a rotating speed of 500rpm, cooling, and filtering to obtain the vehicle gear oil composite additive.

Comparative example 1

The comparative example provides a compound additive of vehicle gear oil, which is manual gearbox gear oil produced by China Petroleum oil company, the oil change mileage is more than 10 ten thousand kilometers, the main components of the compound additive of the gear oil are an extreme pressure antiwear agent, an anti-corrosion antirust agent, a detergent dispersant and an antioxidant, and the additive amount of the compound additive is 8.55wt% of the total amount of the gear oil.

Comparative example 2

The comparative example provides a vehicle gear oil composite additive which is produced by the yafuton company, and the composite additive is subjected to 50-ten-thousand-mile driving test in a heavy truck, has good bearing, sintering resistance, oxidation resistance and corrosion resistance, and the addition amount of the composite additive is 11.2 weight percent of the total amount of the gear oil.

Comparative example 3

This comparative example provides a vehicle gear oil composite additive manufactured by yafuton, which was tested in a heavy truck for 30 ten thousand kilometers, and which was added to synthetic base oil in an amount of 8.0wt%.

Comparative example 4

The comparative example provides a compound additive for vehicle gear oil, the compound additive is produced by road-run, the heat stability of the compound additive is far higher than SAE J2360 requirement, the compound additive has better oxidation stability, the oil change mileage is 50 kilometers, and the additive amount of the compound additive in 75W-grade vehicle gear oil is 12.0wt%.

Performance testing

Rubber compatibility test: the rubber compatibility test was performed according to the petrochemical industry standard SH/T0429-2007 of the people's republic of China, the compatibility test of lubricating grease and liquid lubricant with rubber.

The method comprises the following steps: the composite additives of example 1 and example 3 were added to a synthetic base oil of 75W-90 viscosity grade (the component proportions are shown in table 1), stirred at room temperature for 1 to 2 hours, and prepared into a 75W-90 vehicle gear oil, and then rubber compatibility tests were conducted on the 75W-90 vehicle gear oils prepared in example 1 and example 3, wherein the addition amount of the composite additive of example 1 was 11.35wt% of the total mass of the synthetic base oil of 75W-90 viscosity grade, and the addition amount of the composite additive of example 3 was 12.0wt% of the total mass of the synthetic base oil of 75W-90 viscosity grade; meanwhile, rubber compatibility tests are also respectively carried out on the similar products 1 to 3 sold in the market; the test results are shown in Table 2.

From the comparison results in Table 2, it is clear that the rubber compatibility of the oil products prepared by the composite additive in example 1 and example 3 is equivalent to that of the commercial similar products 1 to 3, and the problem of oil leakage caused by the influence of lubricating oil on the mechanical properties of the rubber in the long-term use process can be effectively avoided.

Fe element content and PQ index test: the Fe element content was measured according to the national standard GB/T17476 and the PQ index was measured using the ASTM D8184 standard.

The method comprises the following steps: the composite additive in the example 5 is added into synthetic base oil with the viscosity grade of 85W-90 (the component proportion is shown in the table 1), stirred for 1-2 hours at normal temperature to prepare oil products, the prepared oil products and the commercial like products 4 are respectively added into a loader axle with the same model, the oil products in the example 5 use 717 hours, the commercial like products 4 use 495 hours to respectively sample and test, and the test results are shown in the table 3.

The PQ index in Table 3 means that when a sample containing ferromagnetic abrasive grains is placed in a magnetic field of a PQ index analyzer, the PQ index analyzer measures the change of the magnetic field generated thereby, and shows that the result is PQ index (dimensionless quantitative number) which has a good linear relationship with the content of iron filings in the sample and the size of the grains; the PQ index is more sensitive to large size (much greater than 10 microns) ferromagnetic abrasive particles, while the Fe element content tested by GB/T17476 is predominantly less than 10 microns of abrasive particles or material; compared with the similar oil product 4 sold in the market, the 85W-90 oil product prepared by the composite additive in the embodiment 5 can obviously reduce the abrasion of gears in the actual application process, thereby effectively ensuring the service life of the gear box to be prolonged.

Table 1, 75W-90, 75W-140 and 85W-90 viscosity grade synthetic base oils

The components	75W-90 viscosity grade	Viscosity grade of 75W-140	85W-90 viscosity grade
				CTL 4 (API III type + base oil)	52 parts of	0	0
CTL 10 (API III type + base oil)	0	52 parts of	0
				PAO 150 (polyalphaolefin base oil)	38 parts of	38 parts of	53 parts
3970 (polyol esters)	10 parts of	10 parts of	0
				400SN (API type I base oil)	0	0	35 parts of

Table 2, example 1, and example 3 rubber compatibility test results of the composite additive-formulated 75W-90 vehicle gear oil with commercially available like products 1-3

Table 3, 85W-90 vehicle gear oil 717h formulated with the composite additive of example 5 and commercially available like product 4 at 495h, the Fe element content and PQ index of the oil

Project	Example 5	Commercial product 4
			Fe element content/ppm	121	281
PQ index	90	140

In addition, the composite additives of examples 1 to 5 and comparative examples 1 to 4 were added to synthetic base oils (the component proportions are shown in Table 1) having a viscosity grade of 75W-140 to blend into corresponding oils, and then performance tests were conducted on the oils of examples 1 to 5 and comparative examples 1 to 4, comprising: appearance, odor, corrosion resistance, rust resistance, load bearing and anti-sintering properties, wear resistance, oxidation resistance, anti-foaming properties; wherein: the amount of the composite additive added to the oil product of example 1 was 11.35wt% based on the total mass of the synthetic base oil having a viscosity grade of 75W-140 (the composition ratios are shown in Table 1), the amounts of the composite additives added to the oil products of examples 2 to 5 were 12.0wt% based on the total mass of the synthetic base oil having a viscosity grade of 75W-140, and the amounts of the composite additives added to the oil products of comparative examples 1 to 4 were 8.55wt%, 11.2wt%, 8.0wt% and 12.0wt%, respectively.

Appearance: the oil products in examples 1 to 5 are stirred for 1 to 2 hours at normal temperature, the oil products in comparative examples 1 to 4 are stirred for 1 to 2 hours at 60 to 65 ℃, and then the appearances of the oil products in examples 1 to 5 and comparative examples 1 to 4 are observed, so that the solubility of the composite additive can be judged according to the appearances; the test results are shown in Table 4.

Smell: testing according to the standard of the popular smell detection VW 50180; the method comprises the following steps: 20g of the oils of examples 1 to 5 and comparative examples 1 to 4 were placed in a sealed odorless bottle, and the sealed bottle was heated in an oven at 60℃for 2 hours, and then the measurement was started, and 5 testers evaluated the odor, and the test results were classified into 6 grades in total: 1 is odorless; 2 is slightly odorous; 3 is tasty, but not irritating; 4 is pungent odor; 5 is a strong pungent odor; 6 is an intolerable taste; the test results are shown in Table 4.

Corrosion resistance: according to the national standard GB/T5096, the copper sheet corrosion test method of petroleum products is carried out under the test conditions of 121 ℃ for 3 hours, and the grades are 1a, 1b, 2a, 2b and 2c; the test results are shown in Table 4.

Rust inhibitive performance: according to national standard GB/T11143, an anti-rust performance measurement method of inhibitor-added mineral oil in the presence of water is carried out; the test results are shown in Table 4.

Load bearing and anti-sintering properties: according to national standard GB/T3142, a lubricating oil bearing capacity measurement method (four ball machine); the maximum seizure free load PB value and the sintering load PD value were obtained, and the specific test results are shown in Table 4.

Wear resistance: according to the industry standard SH/T0189, a method for measuring the abrasion resistance of lubricating oil (four-ball machine) is used for measuring the average value of the long mill patch diameter WSD and the friction coefficient of each oil product at 392N, the average value of the long mill patch diameter WSD and the friction coefficient at 981N, and the average value of the long mill patch diameter WSD and the friction coefficient of the oxidized oil product at 981N, and specific test results are shown in Table 4.

And (3) oxidation resistance test: adding 30mL of test oil into a 50mL beaker, immersing a chromium alloy bearing steel GCr15 steel ball and a copper wire in the test oil, placing the test oil in an oven with the temperature controlled at 135 ℃ for baking for 90 hours, then taking out the steel ball and the copper wire, flushing the steel ball and the copper wire with petroleum ether, observing the color change condition of the steel ball and the copper wire, and simultaneously observing the condition of sediment at the bottom of the cup, wherein more, less and no distinction exists between oxidized sludge in the oven at the bottom of the cup; wherein the rating of the oven oxidized steel ball and the oven oxidized copper wire specifies: 0 is non-discoloring; 1 is slightly discolored and is almost the same as the new sample; 2 is local color change; 3 is overall color change, and becomes bright after wiping; 4, the surface is red, yellow, blue, gray and other colors or has gray-white sediment; 5 is a local gray black, and is obviously corroded; 6 is grey black, and peels off; the specific test results are shown in Table 4.

Anti-foam performance test: according to the national standard GB/T12579-2002 lubricating oil foam characteristic determination method; the specific test results are shown in Table 4.

Table 4, results of Performance test of the oils prepared by adding the composite additives of examples 1 to 5 and comparative examples 1 to 4 to synthetic base oils having a viscosity of 75W-140

The results show that the composite additive in the examples 1-5 has better solubility in the synthetic base oil, can effectively reduce the development difficulty of the synthetic vehicle gear oil, and is equivalent to or better than a part of products in the comparative examples in aspects of smell, corrosion resistance, rust resistance and the like; namely, the composite additive has the characteristics of outstanding extreme pressure antiwear performance, good solubility and good oxidation stability, and can meet the requirements of vehicle gears on lubricating, corrosion preventing and rust preventing properties; compared with the commercial vehicle gear oil composite additive (comparative examples 2 and 4) with 50 ten thousand kilometers of oil change mileage, the prepared oil product has better wear resistance retention capacity before and after high-temperature decay, and has the performance equivalent to that of the commercial long-service-life vehicle gear oil composite additive.

Heavy load variable rotation speed test: the oil temperature is controlled to be 75 ℃ on a four-ball machine, 100kg of load is loaded, the initial rotating speed is 20rpm, the operation is carried out for 30 seconds at each rotating speed, then the rotating speed is increased by 20rpm until the maximum rotating speed is 2800rpm, the test lasts for 70 minutes, the friction coefficient and the temperature change of the oil product are recorded in the test process, and the size of grinding marks on the surface of the steel ball is observed and measured after the test is finished.

Referring to fig. 1 to 5, which are graphs of friction coefficients obtained by carrying out heavy load variable speed tests on the oil products prepared in examples 1, 5, 2 and 4, the results show that the oil products prepared by the composite additives in examples 1 and 5 have good antifriction and antiwear properties; FIG. 7 is a graph showing the temperature change of the oil products prepared in examples 1, 2, 5, 2 and 4 according to the present invention during the heavy load variable rotation speed test, wherein the maximum temperature difference of the oil products in example 1 is 14.2 ℃, the maximum temperature difference of the oil products in example 2 is 6.4 ℃, the maximum temperature difference of the oil products in example 5 is 6.4 ℃, the maximum temperature difference of the oil products in comparative example 2 is 36.2 ℃, and the maximum temperature difference of the oil products in comparative example 4 is 39.2 ℃; as can be seen from fig. 2 to 6, the diameter of the grinding mark on the surface of the steel ball in example 1 is 0.773mm, the diameter of the grinding mark on the surface of the steel ball in example 5 is 0.769mm, the diameter of the grinding mark on the surface of the steel ball in comparative example 2 is 1.452mm, and the diameter of the grinding mark on the surface of the steel ball in comparative example 4 is 1.682mm; namely, the composite additive has the advantages of outstanding extreme pressure antiwear performance and good oxidation stability.

Oil life assessment test: the method for judging the service life of the gear oil is mainly referred to 2018 Liao Feng and the like in Chinese lubrication technical forum and in the paper of Long-life vehicle gear oil research published in China society of automotive engineering and automobile fuel and lubricating oil, and is characterized in that the service life of the gear oil is judged from three aspects of oxidative deterioration of the oil itself, abrasion resistance and oil corrosion; the oxidation and deterioration of the oil product and the corrosion test of the oil product are reflected by the oil sludge generation amount and the steel ball and copper wire rating in a 90-hour oven oxidation test.

Wherein, the oil products prepared in the examples 1, 5 and the comparative examples 2, 3 and 4 pass through the 90h oven oxidation test, the oil sludge generation amount is shown in fig. 6, and the rating results of the steel balls and the copper wires are shown in table 4; the abrasion resistance is reduced by examining the abrasion resistance change condition after the oil is decayed through a heavy load rotation speed changing test, has better abrasion resistance retention capacity before and after the high temperature decay, and is equivalent to the performance of the commercial long-life vehicle gear oil complexing agent.

Compared with the oil products blended by the composite additives at home and abroad, the oil products prepared by the composite additives in the examples 1-5 have good antifriction, anti-wear, anti-sintering and high temperature resistance, and the anti-wear performance of the oil products after high temperature decay can be kept better, so that the gear set running under heavy load condition can be protected for a long time.

In summary, the vehicle gear oil composite additive disclosed by the invention adopts the mixture of high-pressure vulcanized olefin and/or normal-pressure vulcanized olefin as a sulfide extreme pressure agent, and various phosphorus-nitrogen additives as antiwear agents, and the performance characteristics of the vulcanized olefin prepared by different processes can be brought into play by mixing the normal-pressure vulcanized olefin and the high-pressure vulcanized olefin, and meanwhile, the synergistic effect of the sulfide extreme pressure agent and the antiwear agents is fully brought into play, so that the vehicle gear oil composite additive has excellent extreme pressure antiwear characteristics; in addition, the composite additive contains a detergent dispersant and an anti-foaming agent, so that the anti-foaming agent is firstly uniformly dispersed in the composite additive, and the phenomenon that the oil is heated and severely stirred to ensure that the anti-foaming performance of the oil is qualified during oil blending is avoided; and the composite additive is in The API III and above total synthetic base oil has excellent solubility, and if the base oil component does not contain super-high viscosity components such as viscosity index improver (kinematic viscosity at 100deg.C is greater than 200 mm) ² S), the oil product can be prepared at normal temperature without heating, and the appearance and the anti-foam performance of the oil product are not obviously changed after long-term storage, so that the energy consumption in the oil product blending process is greatly reduced, the blending efficiency is improved, and the oil product production cost is reduced; the vehicle gear oil composite additive contains a sulfur-free and phosphorus-free friction improver, wherein a nitrogen atom in the structure of the sulfur-free and phosphorus-free friction improver is provided with lone pair electrons, an ordered molecular adsorption film is formed on the surface of a metal, friction and abrasion on the surface of a metal friction pair are reduced, and the anti-friction performance of lubricating oil is improved, so that the temperature rise of the oil in the use process is inhibited; in addition, the compound additive takes shielding phenol and aromatic amine as antioxidants and is matched with the oil sludge dispersing effect of a detergent dispersant and an antiwear agent with good thermal stability, so that the compound additive has good high-temperature oxidation resistance, insoluble matters such as oil sludge and the like are not easy to generate at high temperature, and the antiwear performance of an oil product after high-temperature decay is kept good, thereby improving the oil change mileage of the oil product, and the oil change mileage of the oil product prepared by the compound additive is more than 20 ten thousand kilometers; in addition, the vehicle gear oil composite additive can pass a synthetic seawater liquid phase rust test without adding an antirust agent, and the salt fog resistance of an oil product prepared by the additive is better than that of conventional gear oil, so that gears can be effectively protected from being corroded and rusted, and the service life of a gear set is prolonged; according to the invention, 12.0wt% of the composite additive is added into the blended 75W-140 viscosity grade base oil, the antiwear property of the oil is obviously superior to that of the oil prepared by various commercial high-end vehicle gear oil composite additives, and the gear set running under high load can be well protected. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims

1. The composite additive for the vehicle gear oil is characterized by comprising the following components in parts by mass: 18 to 80 parts of sulfide extreme pressure agent, 10 to 30 parts of antiwear agent, 0 to 10 parts of sulfur-free phosphorus type friction modifier, 10 to 50 parts of detergent dispersant, 0 to 10 parts of antioxidant, 0 to 5 parts of metal deactivator and 0.1 to 1 part of anti-foaming agent.

2. The vehicle gear oil composite additive according to claim 1, wherein: the composite additive comprises the following components in parts by mass: 28-70 parts of sulfide extreme pressure agent, 14-25 parts of antiwear agent, 0-10 parts of sulfur-free phosphorus type friction modifier, 15-40 parts of detergent dispersant, 3-6 parts of antioxidant, 0-3 parts of metal deactivator and 0.1-0.5 part of anti-foaming agent.

3. The vehicle gear oil composite additive according to claim 1, wherein: the sulfide extreme pressure agent is one or a combination of high-pressure vulcanized olefin and normal-pressure vulcanized olefin, wherein the sulfur content in the high-pressure vulcanized olefin is 42-46 wt%; the sulfur content in the normal pressure vulcanized olefin is 40-45 wt%.

4. The vehicle gear oil composite additive according to claim 1, wherein: the antiwear agent is one or a combination of acid phosphate amine salt and nitrogenous heterocyclic phosphite amine salt.

5. The vehicle gear oil composite additive according to claim 1, wherein: the sulfur-free phosphorus type friction improver is an amine compound, and the structural general formula of the amine compound is as follows:

6. The vehicle gear oil composite additive according to claim 1, wherein: the detergent dispersant is one or a combination of polyisobutylene succinimide and boronated polyisobutylene succinimide.

7. The vehicle gear oil composite additive according to claim 1, wherein: the antioxidant is one or a combination of shielding phenol and aromatic amine.

8. The vehicle gear oil composite additive according to claim 1, wherein: the metal deactivator is one or combination of benzotriazole, thiadiazole and imidazoline derivatives.

9. The vehicle gear oil composite additive according to claim 1, wherein: the anti-foaming agent is one or a combination of organosilicon polymers and non-organosilicon polymers.

10. A method for preparing the vehicle gear oil composite additive according to any one of claims 1 to 9, characterized in that: the preparation method comprises the following steps:

11. A method for preparing the vehicle gear oil composite additive according to any one of claims 1 to 9, characterized in that: the preparation method comprises the following steps:

12. Use of a vehicle gear oil complex additive according to any one of claims 1 to 9, characterized in that: the composite additive is applied to vehicle gear oil, wherein the addition amount of the composite additive in the gear oil is not more than 12wt% based on 100% of the mass of the gear oil.